Manufacturing of adeno-associated viruses, for example: AAV2

Native Digestion and Shotgun Proteomics for Host Cell Protein Profiling of Adeno-Associated Viruses

Host cell proteins (HCPs) are contaminants of biotherapeutics produced from engineered living systems; they can influence the product's quality, efficacy, and toxicity. Liquid chromatography coupled to mass spectrometry can detect HCPs thereby mitigating their risks. However, highly abundant biotherapeutics hamper the detection of low-level HCPs. Sample preparation termed native digestion has proven effective to preferentially digest and draw out HCPs from intact antibodies. Here, we adapted native digestion to adeno-associated viruses (AAV), which is a vector gaining popularity for gene therapy. We leveraged quantitative proteomics using capillary-flow liquid chromatography-mass spectrometry (LC-MS) and demonstrated that native digestion was more effective than applying denaturing conditions to extract the HCPs associated with different AAV serotypes.

A Methodological Approach Using rAAV Vectors Encoding Nanobody-Based Biologics to Evaluate ARTC2.2 and P2X7 In Vivo

On murine T cells, mono-ADP ribosyltransferase ARTC2.2 catalyzes ADP-ribosylation of various surface proteins when nicotinamide adenine dinucleotide (NAD⁺) is released into the extracellular compartment. Covalent ADP-ribosylation of the P2X7 receptor by ARTC2.2 thereby represents an additional mechanism of activation, complementary to its triggering by extracellular ATP. P2X7 is a multifaceted receptor that may represents a potential target in inflammatory, and neurodegenerative diseases, as well as in cancer. We present herein an experimental approach using intramuscular injection of recombinant AAV vectors (rAAV) encoding nanobody-based biologics targeting ARTC2.2 or P2X7. We demonstrate the ability of these in vivo generated biologics to potently and durably block P2X7 or ARTC2.2 activities in vivo, or in contrast, to potentiate NAD⁺- or ATP-induced activation of P2X7. We additionally demonstrate the ability of rAAV-encoded functional heavy chain antibodies to elicit long-term depletion of T cells expressing high levels of ARTC2.2 or P2X7. Our approach of using rAAV to generate functional nanobody-based biologics in vivo appears promising to evaluate the role of ARTC2.2 and P2X7 in murine acute as well as chronic disease models.